When a parent is about to embark on a restrictive diet to help their child based on anecdotal experiences of other parents – it is best to cast a wide net and get as much input as possible. I have got opinions on the eficacy of this diet from a large number of parents from all over the world and have posted them online in this link:
It is clear that it is a no brainer to try the diet out with your child.
Here is a double blind study on the diet
While not conclusive the authors acknowledge the requirement for further work to be done in this area.